ruby-install 0.3.4

### 0.3.4 / 2013-12-25

* Use the `.part` file extension for files being downloaded, to distinguish
  between already downloaded files.

#### ruby

* Added versions for 2.1.0-rc1 and 2.1.0.

#### jruby

* Added version for 1.7.9.

#### rubinius

* Added version for 2.2.2.